So I own a 2.4ltr kinetic Volvo v50 and I have to keep adding the coolant into the reservoir every 50 Kms but I found recently that the passenger footwell has had a green liquid that has been collecting in the footwell, on google search it said I have to remove the dashboard as it may be the heater element?
any help or advice?

 

Yes, it sounds like the heater core (inside the bowels of the dash) is leaking. I've never had to mess with one of those, but there should be online resources that will show you what's involved. You may have more luck searching for a similar year S40 heater core though (a lot more of them, and it should be the same).

 

Check Youtube for vids on how to access. I've never done an S40 but on the 850 you remove the sides of the center console to expose the heater core and it will slide out to the passenger footwell. Check to make sure the o-rings are good as they can fail as well. If you decide to replace on your own, you'll want to drain the radiator as best you can, then use a trashbag to collect the coolant from the core when you pop off the line (lol and have your shop vac handy...)